Trim Fin?-gctid345516

[Guest]

I purchased a 1983 Contessa Command Bridge last year. I am running the Volvo AQ260 and I believe it has a 290 outdrive to it. It got dumped in the water last year without me watching and it had a large amount of wander to the steering at almost all speeds this year. When I pulled it I discovered my trim fin is missing. I looked at a twin boat to mine and his trim fin is missing also. Has the same issues. Is anyone running their boat with a trim fin? If you have had it on or off the boat have you noticed a large difference in steering control?

Thanks

Mike

[Guest]

On mine I had the trim fin , but it didnt make much difference at any speed, if you have the 280sp drive you will always fight that steering, it seemed to me to be the nature of the beast. But I dont have that drive anymore and dont miss it one bit.images/smilies

[Guest]

Ofishal wrote:
On mine I had the trim fin , but it didnt make much difference at any speed, if you have the 280sp drive you will always fight that steering, it seemed to me to be the nature of the beast. But I dont have that drive anymore and dont miss it one bit.images/smilies

Thank you. I had a feeling it was a built in problem.

[Guest]

The problem is is the torque of the single prop and cable steering, not sure but maybe hydraulic steering may help. Check out the seastar/baystar systems by teleflex they may help a bit. I remember having to constantly hold and fight the steering wheel at speeds, maybe someone here has done a hydraulic conversion on a 280 sp? I changed everything so dont know if there is a better/cheaper solution? Good Luck:greedy_dollars:

[2850Bounty]

Most all sterndrives will undergo steer torque from propeller rotational forces........ it's just the nature of prop thrust with an I/O.

Also, this will usually not be the same at each RPM/Speed range.

A drive with Hydraulic steering, No-Feed-Back steering or Power Assist steering, will not allow the helmsman to feel this torque.

Sounds good, right?

Here's the catch with that:

While the helmsman doesn't feel this, all of the steering components (spindle arm, collar steering fork and bushings, helmet, helmet pin, and even the suspension fork) still undergo this torque.

This can cause premature wear.

IOW, these steering systems only "mask" the steer torque, so we don't actually feel it at the helm wheel.

So we end up paying little attention to it until things are worn so severely that they need costly attention.

I would suggest installing and adjusting the trim fin/torque tab best you can.



Your excessive side-to-side play is very likely due to worn collar steering fork (seq #2) bushings (seq # 10 & 11).

275/280 style components



There should be a thread or two on the R&R of these mentioned in my BOC Vault thread.

A photo of your drive will tell me which one you have.

1983... likely a 280 on a Contessa..... will not have power trim.

The 290 was several years later..... will have power trim.

[Guest]

2850Bounty wrote:
Most all sterndrives will undergo steer torque from propeller rotational forces........ it's just the nature of prop thrust with an I/O.

Also, this will usually not be the same at each RPM/Speed range.

A drive with Hydraulic steering, No-Feed-Back steering or Power Assist steering, will not allow the helmsman to feel this torque.

Sounds good, right?

Here's the catch with that:

While the helmsman doesn't feel this, all of the steering components (spindle arm, collar steering fork and bushings, helmet, helmet pin, and even the suspension fork) still undergo this torque.

This can cause premature wear.

IOW, these steering systems only "mask" the steer torque, so we don't actually feel it at the helm wheel.

So we end up paying little attention to it until things are worn so severely that they need costly attention.

I would suggest installing and adjusting the trim fin/torque tab best you can.



Your excessive side-to-side play is very likely due to worn collar steering fork (seq #2) bushings (seq # 10 & 11).

275/280 style components



There should be a thread or two on the R&R of these mentioned in my BOC Vault thread.

A photo of your drive will tell me which one you have.

1983... likely a 280 on a Contessa..... will not have power trim.

The 290 was several years later..... will have power trim.

There is the next question answered....I was wondering what actual drive it was.

[Guest]

2850Bounty wrote:
Most all sterndrives will undergo steer torque from propeller rotational forces........ it's just the nature of prop thrust with an I/O.

Also, this will usually not be the same at each RPM/Speed range.

A drive with Hydraulic steering, No-Feed-Back steering or Power Assist steering, will not allow the helmsman to feel this torque.

Sounds good, right?

Here's the catch with that:

While the helmsman doesn't feel this, all of the steering components (spindle arm, collar steering fork and bushings, helmet, helmet pin, and even the suspension fork) still undergo this torque.

This can cause premature wear.

IOW, these steering systems only "mask" the steer torque, so we don't actually feel it at the helm wheel.

So we end up paying little attention to it until things are worn so severely that they need costly attention.

I would suggest installing and adjusting the trim fin/torque tab best you can.



Your excessive side-to-side play is very likely due to worn collar steering fork (seq #2) bushings (seq # 10 & 11).

275/280 style components



There should be a thread or two on the R&R of these mentioned in my BOC Vault thread.

A photo of your drive will tell me which one you have.

1983... likely a 280 on a Contessa..... will not have power trim.

The 290 was several years later..... will have power trim.

Hey Rick question........

The catch you mention does that apply to DP's as well? I would think the counter rotating props counter act the torque of the other prop, no?

[2850Bounty]

Ofishal wrote:
Hey Rick question........ The catch you mention does that apply to DP's as well? I would think the counter rotating props counter act the torque of the other prop, no?

The catch still applies because the forward prop is first to cut the water and the smaller but more aggressive pitch aft prop thrusts off of the forward one.

[Guest]

Ofishal wrote:
I would think the counter rotating props counter act the torque of the other prop, no?

The common understanding in the industry is that duorops do elimitate most, if not all, prop steer and lateral torque. Volvo says "The counter rotating twin propellers eliminates the lateral forces existing in conventional single prop sterndrives."

[2850Bounty]

orca wrote:
The common wisdom in the industry is that duorops do elimitate most, if not all, prop steer and lateral torque. Volvo says "The counter rotating twin propellers eliminates the lateral forces existing in conventional single prop sterndrives."

See SEQ #7 p/n 854054 "fin" (aka Torque Tab or Trim Fin) shown below. This part is designed and produced by Volvo Penta.



For OEM Volvo Penta torque tab adjustment for both the SP and DP drives, https://"http://www.thestraycat.net/...file page 140.

.

[Guest]

Guess Volvo is a bit overzealous with the marketing. Nice to know that it isn't completely eliminated, contrary to what most folks say. But an 83% reduction is pretty darn good. The setting for single prop is 30 degrees, while it is only 5 degrees for duo prop.